According to the wiki page, the Wizarding World of Harry Potter at Universal Orlando Resort cost Universal around 256 million to put together. While that might seem like a crazy amount, that's just a drop in the bucket compared to what Universal spent on Super Nintendo World.
Japanese publication Sankei has published an article about the recently-revealed details for Super Nintendo World, but they go over one aspect that we haven't seen covered anywhere else. According to their info, Universal has spent around 545 million dollars on Super Nintendo World. This would make it the highest price Universal has ever spent on a new park.